VARIATIONS IN THE TYPE OF INFLAMMATION. 255 



The function of the serous exudate is quite probably pri- 

 marily nutritive. Further, it frequently possesses bactericidal 

 properties, and may be of value in diluting any bacterial 

 poison present at the site of inflammation. On the other 

 hand, however, the serum is often an extremely good culture- 

 medium for various varieties of micro-organisms, so that its 

 presence may not always result advantageously to the tissue. 



Connective-tissue changes : l We have noted that in addition 

 to their phagocytic function the migrated leukocytes are 

 capable of playing an important part in repair, by developing 

 into connective-tissue elements; and further, on the other 

 hand, that young connective-tissue cells and endothelial cells 

 of bloodvessels, active proliferative changes in which are 

 always noted from the very onset of all inflammatory processes, 

 are markedly phagocytic, though this certainly cannot be 

 looked upon as their sole function. It would seem that these 

 are good arguments to extend our conception of inflammation 

 beyond a simple phagocytic reaction on the part of the animal 

 organism. There are examples of non-infectious inflamma- 

 tion where the leukocytic migration is most marked, though 

 not necessarily phagocytic in its nature, in the sense in which 

 the term is usually employed. 



Synchronous with the blood-vascular alterations at the 

 outset of inflammation, to which are always added more or 

 less marked degenerative changes in, or even complete destruc- 

 tion of, certain of the cellular elements according to the 

 severity of the irritant, active proliferative changes in the 

 fixed connective-tissue cells occur, which must be regarded 

 as a restorative as well as a defensive manifestation, and hence 

 should be included in our conception of inflammation. We 

 conclude that inflammation is a purposive reaction, having 

 for its object the neutralization of the effects of an injury. 

 In this sense, then, we should include under the head of in- 

 flammation the phenomena of repair. Undoubtedly their 

 significance is the same ; but in speaking of inflammation we 

 have in mind a well-defined clinical picture which here is 

 absent the only difference in the phenomena, however, being 

 one of degree. 



Variations in the type of inflammation: In every inflamma- 



1 See under head of Repair, 



